WO2007094192A1

WO2007094192A1 - Resist composition for immersion lithography and method for formation of resist pattern

Info

Publication number: WO2007094192A1
Application number: PCT/JP2007/051945
Authority: WO
Inventors: Makiko Irie; Takeshi Iwai
Original assignee: Tokyo Ohka Kogyo Co., Ltd.
Priority date: 2006-02-17
Filing date: 2007-02-05
Publication date: 2007-08-23
Also published as: JP2007249152A; US20090042132A1; JP4912733B2; US8394569B2; TWI383260B; TW200801810A; KR20080085235A; KR101032019B1

Abstract

Disclosed is a resist composition for immersion lithography comprising: a resin component (A) whose alkali solubility can vary by the action of an acid; and an acid-generator component (B) which can generate an acid when exposed to light. The resin component (A) contains a fluorine atom and comprises a resin (A1) and a resin (A2), wherein the resin (A1) has no acid-dissociating group and the resin (A2) has a constituent unit (a’) derived from acrylic acid and contains no fluorine atom.

Description

Specification

Resist composition for immersion exposure and method for forming resist pattern

Technical field

The present invention relates to a resist composition for immersion exposure and a resist pattern forming method used for immersion exposure (immersion lithography).

This application claims priority based on Japanese Patent Application No. 2006-041116 filed on February 17, 2006 and Japanese Patent Application No. 2006-122330 filed on April 26, 2006. Is hereby incorporated by reference.

Background art

[0002] Lithography method is frequently used for the manufacture of fine structures in various electronic devices such as semiconductor devices and liquid crystal devices. With the miniaturization of device structures, the resist pattern has become finer in the lithography process. It is requested. Currently, it is possible to form a fine resist pattern with a line width of about 90 nm in the most advanced area using, for example, an ArF excimer laser by the lithographic method. Pattern formation is required.

In order to achieve such a fine pattern formation, the development of an exposure apparatus and a corresponding resist is the first.

As a resist, high resolution is achieved, and the catalytic reaction and chain reaction of acid generated by radiation irradiation can be used, and the quantum yield is 1 or more, and high sensitivity can be achieved. Amplified resists are attracting attention and are being actively developed.

In a positive chemically amplified resist, a resin having an acid dissociable, dissolution inhibiting group is mainly used. As the acid dissociable, dissolution inhibiting group, for example, an acetal group such as an ethoxyethyl group, a tertiary alkyl group such as a tert butyl group, a tert butoxycarbonyl group, a tert-butoxycarbonylmethyl group and the like are known. In addition, as a structural unit having an acid dissociable, dissolution inhibiting group in a resin component of a conventional ArF resist composition, as shown in Patent Document 1 below, a tertiary ester compound of (meth) acrylic acid is used. For example, 2 alkyl-2-adamantyl (meth) atallylate isotope-derived structural units are commonly used. ing.

On the other hand, in an exposure apparatus, it is common to shorten the wavelength of a light source to be used, increase the numerical aperture (NA) of a lens (to increase NA), or the like. For example, in general, the g-line with the main spectrum of the mercury lamp is 436 nm with a resist resolution of about 0.3, and the i-line with the main spectrum of the mercury lamp of 365 nm is also used with about 0.5 to 0.30. A 248 nm KrF excimer laser beam is used at about 0.30 to 0.15 m, and a 193 nm ArF excimer laser beam is used at about 0.15 m or less. For further miniaturization, F excimer laser (157 nm), Ar excimer laser (126 nm), EUV (extra pole)

twenty two

Edge ultraviolet rays (13.5 nm), EB (electron beam), X-rays, etc. are being studied.

However, shortening the wavelength of the light source requires an expensive new exposure apparatus. In addition, when NA is increased, there is a tradeoff between resolution and depth of focus, so there is a problem that the depth of focus decreases even if the resolution is increased.

[0005] In such circumstances, a method called immersion exposure (immersion lithography) has been reported (for example, see Non-Patent Documents 1 to 3). In this method, during exposure, the portion between the lens, which has been filled with an inert gas such as air or nitrogen, and the resist film on the wafer is larger than the refractive index of air! It is a method including a step of performing exposure (immersion exposure) in a state filled with a solvent (immersion medium).

According to such immersion exposure, even when a light source with the same exposure wavelength is used, the same high resolution as when using a light source with a shorter wavelength or using a high NA lens can be achieved, and moreover, It is said that there is no drop in the depth of the point. In addition, immersion exposure can be performed using an existing exposure apparatus. For this reason, it is expected that immersion exposure can realize formation of a resist pattern with low cost, high resolution, and excellent depth of focus. Also, in the manufacture of semiconductor devices that require a large amount of capital investment, it has attracted a great deal of attention as having a great effect on the semiconductor industry in terms of cost and resolution characteristics such as resolution. Currently, water is mainly studied as an immersion medium.

Patent Document 1: JP-A-10-161313

Non-Patent Document 1: Journal of Vacuum Science & Technology B (USA), 1999, Vol. 17, No. 6, 3306-3 Non-Patent Document 2: Journal of Vacuum Science & Technology B (USA), 2001, 19th, No. 6, 2353-2 356.

Non-Patent Document 3: Proceedings of SPIE (USA) 2002, 4691, 459-465.

Disclosure of the invention

Problems to be solved by the invention

However, it is actually difficult to form a fine pattern with many unknown points in immersion exposure at a level where it can actually be used. For example, in immersion exposure, as described above, the immersion medium comes into contact with the resist film and the lens during immersion exposure. For this reason, the resist film changes its quality due to elution of the substance contained in the resist into the immersion medium, etc., and its performance deteriorates, or the refractive index of the immersion medium is locally changed or eluted by the eluted substance. It is conceivable that the material may adversely affect the lithography characteristics due to contamination of the lens surface. In other words, problems such as deterioration in sensitivity, the resulting resist pattern force-top shape, and swelling if the resist pattern surface becomes rough are expected.

As a means for solving such a problem, for example, it is conceivable to improve the resistance of the resist film to the immersion medium (immersion medium resistance). At present, water-based solvents such as water are mainly studied as the immersion medium. Therefore, it is estimated that increasing the hydrophobicity of the resist film is effective in improving the immersion medium resistance.

However, in order to increase the hydrophobicity of the resist film, it is necessary to change the resist composition, and the change in the resist composition usually deteriorates the lithography characteristics. Therefore, even if the hydrophobicity of the resist film is increased for use in immersion exposure, it is difficult to form a fine pattern on the resist film at a practically usable level. The present invention has been made in view of the above circumstances, and is suitable for immersion exposure, and also has excellent lithography properties and resist pattern formation for resist and immersion resist pattern formation. It aims to provide a method.

Means for solving the problem

[0007] As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by using an acrylic resin and a specific fluorine atom-containing resin in combination, and have completed the present invention. That is, the first aspect (aspect) of the present invention is an immersion exposure light comprising a resin component (A) whose alkali solubility is changed by the action of an acid and an acid generator component (B) which generates an acid upon exposure. A resist composition for

The resin component (A) has a fluorine atom-containing resin (A1) having no acid-dissociable group, an acrylic acid power-derived structural unit (a ′), and a fluorine atom. A resist composition for immersion exposure containing a resin (A2) that does not contain.

The second aspect of the present invention includes a step of forming a resist film on a substrate using the resist composition for immersion exposure according to the first aspect, a step of immersion exposure of the resist film, and the resist film. A resist pattern forming method including a step of forming a resist pattern by development.

In the present invention, “structural unit” means a monomer unit constituting a polymer (resin).

Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.

A “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.

“Exposure” is a concept that encompasses not only light irradiation but also radiation irradiation such as electron beam irradiation.

The invention's effect

According to the present invention, it is possible to provide a resist composition for immersion exposure and a method for forming a resist pattern that are suitable for immersion exposure and have good lithography properties.

Brief Description of Drawings

FIG. 1 is a diagram for explaining a receding angle (0) and a falling angle (Θ).

1 2

FIG. 2 is a graph showing the relationship between the ratio (mass%) of (A) -1 in the component (A) in Example and the receding angle and the falling angle. FIG. 3 is a graph showing the relationship between the ratio (mass%) of (A) -4 in the component (A) in Examples and the receding angle and the falling angle.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail.

«Resist composition for immersion exposure >>

The resist composition for immersion exposure according to the present invention comprises a resin component (A) whose alkali solubility is changed by the action of an acid (hereinafter referred to as component (A)) and an acid generator component that generates an acid upon exposure. (B) (hereinafter referred to as component (B)).

In the present invention, the component (A) has a fluorine atom-containing resin (A1) that does not have an acid-dissociable group, a structural unit (a ′) that also induces acrylic acid power, and It is necessary to contain a resin (A2) that does not contain fluorine atoms.

Here, in the present specification and claims, the “acid-dissociable group” means a group dissociated by the action of an acid generated from the component (B) by exposure. For example, a lateratone-containing cyclic group in the structural unit (a ′ 2), a polar group-containing aliphatic hydrocarbon group in the structural unit (a ′ 3), and a polycyclic aliphatic carbonization in the structural unit (a ′ 4). Hydrogen groups and the like are not included in “acid-dissociable groups”.

The acid-dissociable group is not particularly limited as long as it is a group that can be dissociated by the action of the acid generated from the component (B). For example, until now, the acid-dissociable, dissolution-inhibiting group of the base resin for chemically amplified resists. It can be used as proposed. Specific examples of the acid dissociable, dissolution inhibiting group include those similar to those exemplified as the acid dissociable, dissolution inhibiting group of the structural unit (a ′ 1) in the structural unit (a ′ 1) described later. .

Here, the “dissolution inhibition” in the acid dissociable dissolution inhibiting group means that the group has an action (dissolution inhibiting property) for inhibiting the solubility of the component (A) in an alkali such as an alkali developer. . In the present invention, the “acid-dissociable group” may have a dissolution inhibitory property or may not have a dissolution inhibitory property.

[0013] The resist composition for immersion exposure according to the present invention is preferably a positive resist composition that may be a negative resist composition or a positive resist composition.

When the resist composition for immersion exposure according to the present invention is a negative resist composition, component (A) Is an alkali-soluble resin, and further, a crosslinking agent (C) is blended in the resist composition. In the negative resist composition, when an acid is generated from the component (B) by exposure during resist pattern formation, the acid acts to cause cross-linking between the alkali-soluble resin and the cross-linking agent, resulting in alkali-insoluble. To change.

As the alkali-soluble coconut resin, the coconut resin having a unit derived from at least one of a- (hydroxyalkyl) acrylic acid or α- (hydroxyalkyl) acrylic acid also having a lower alkyl ester power is selected. This is preferable because a good resist pattern can be formed. It should be noted that a (hydroxyalkyl) acrylic acid is composed of acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably a carbon number) to the α-position carbon atom. One or both of α-hydroxyalkylacrylic acids to which 1 to 5 hydroxyalkyl groups are bonded.

As the crosslinking agent (C), for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, because a good resist pattern with little swelling can be formed. . The compounding amount of the crosslinking agent (C) is preferably in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

[0014] When the resist composition for immersion exposure of the present invention is a positive resist composition, the component (Α) has an acid dissociable, dissolution inhibiting group, and the alkali solubility is increased by the action of an acid. Fat is used. In the positive resist composition containing the component (Α), when an acid is generated from the component (Β) upon exposure at the time of resist pattern formation, the acid dissociates the acid-cleavable dissolution inhibiting group. , (Α) component becomes alkali-soluble. Therefore, in the formation of the resist pattern, when the resist composition applied on the substrate is selectively exposed, the alkali solubility in the exposed portion increases and alkali development can be performed.

[0015] [Oxal (A1)]

The resin (A1) is not particularly limited as long as it contains a fluorine atom and does not have an acid dissociable group.

In the present invention, the resin (A1) preferably has an alkali-soluble group in both positive and negative types. By having an alkali-soluble group, Increases the solubility of Lucari and contributes to the improvement of various lithography properties such as resolution and resist pattern shape. In particular, having an alkali-soluble group containing a fluorine atom, such as a fluorinated hydroxyalkyl group, which will be described later, is excellent in improving the hydrophobicity of the resist film and suppressing the substance elution during immersion exposure. Usefulness for immersion exposure is further improved.

[0016] The alkali-soluble group is a group that enhances the alkali solubility of the resin, and a group having a relatively small pKa (Ka is an acid dissociation constant) similar to a phenolic hydroxyl group is particularly limited. However, groups having a pKa in the range of 6-12 are preferred.

More specifically, examples of the alkali-soluble group include groups having OH at the terminal, such as a hydroxyl group (phenolic hydroxyl group, alcoholic hydroxyl group) and a carboxy group. Specific examples of the alkali-soluble group having OH at the end include, for example, an alcoholic hydroxyl group; a hydrogen atom bonded to a carbon atom to which a hydroxyl group is bonded in a hydroxyalkyl group (the carbon atom at the arrangement) is an electron-absorbing property. Groups substituted with a group (electron-absorbing I-group-substituted hydroxyalkyl group); carboxy group and the like.

Of these, the alkali-soluble group is preferably an electron-withdrawing group-substituted hydroxyalkyl group.

In the electron-withdrawing group-substituted hydroxyalkyl group, the alkyl group is preferably linear or branched. The number of carbon atoms of the electron-withdrawing group-substituted hydroxyalkyl group is not particularly limited, but it is most preferable that 1 to 20 is preferable and 4 to 16 is more preferable.

The number of hydroxy groups is not particularly limited, but is preferably one.

Examples of the electron-withdrawing group include a halogen atom or a halogenoalkyl group. Examples of the rogen atom include a fluorine atom and a chlorine atom. A fluorine atom is preferable. In the halogenated alkyl group, halogen is the halogen atom. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, or a propyl group, more preferably a methyl group or an ethyl group, and most preferably a methyl group. The number of electron-withdrawing groups is 1 or 2, preferably 2.

More specifically and preferably, the electron-withdrawing group-substituted hydroxyalkyl group has a CR ⁷¹ R ⁷² OH group, and R ⁷¹ and R ⁷² are each independently an alkyl group, a halogen atom, or a halogenated alkyl group. And at least one of them is an electron-withdrawing group selected from a halogen atom or a halogenated alkyl group.

[0018] The resin (A1) preferably has a fluorinated hydroxyalkyl group in both cases of positive and negative types. Thereby, the effect of the present invention is improved. It is also effective in reducing defates and LER (Line Edge Roughness: uneven unevenness of line side walls). Diffet is a general defect detected when a developed resist pattern is observed from directly above, for example, with a surface defect observation device (trade name “KLA”) manufactured by KLA Tencor. Examples of defects include scum, bubbles, dust, bridges between resist patterns, uneven color, and precipitates after development.

Here, the “fluorinated hydroxyalkyl group” refers to a hydroxyalkyl group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxy group, and at least the remaining one in the hydroxyalkyl group. One or all hydrogen atoms (hydrogen atoms of an alkyl group not substituted with a hydroxy group) are substituted by fluorine. In the fluorinated hydroxyalkyl group, the hydrogen atom of the hydroxy group can be easily released by fluorination.

[0019] In the fluorinated hydroxyalkyl group, the alkyl group is preferably linear or branched. The number of carbon atoms of the alkyl group is not particularly limited, but 1 to 20 is preferable, 4 to 16 is more preferable, and 4 to 12 is most preferable. The number of hydroxy groups is not particularly limited, but is preferably one.

Among them, as the fluorinated hydroxyalkyl group, a fluorinated alkyl group and Ζ or a fluorine atom are bonded to the carbon atom to which the hydroxy group is bonded (here, the α-position carbon atom of the hydroxyalkyl group). I prefer something.

In particular, a fluorinated alkyl group bonded to the α-position is preferably a perfluoroalkyl group in which all of the hydrogen atoms of the alkyl group are substituted with fluorine.

In the present invention, in particular, rosin (A1) has a group represented by the following general formula (I) Is preferred.

[0020] [Chemical 1]

\

(† H ₂₎ _X

^ 2y + 1 "y," ζ 2ζ + 1

OH (I)

[Wherein, x is an integer of 0 to 5, and y and z are each independently an integer of 1 to 5. In the formula, X is preferably an integer of 0 to 3, and 0 or 1 is particularly preferable.

y and z are preferably integers of 1 to 3, with 1 being most preferred.

[0022] The resin (A1) preferably contains the structural unit (a) derived from acrylic acid even in the case of a positive type or a negative type.

Here, in the present specification and claims, “acrylic acid” means acrylic acid in a narrow sense (CH═CHCOOH), and at least one or all of its hydrogen atoms are other groups or

2

The concept includes a derivative substituted with an atom.

As a derivative of acrylic acid, for example, a substituent (an atom or group other than a hydrogen atom) is bonded to the carbon atom at the a position of acrylic acid in a narrow sense, and a substituted acrylic acid or carboxy of these acrylic acids is used. And acrylic acid esters in which the hydrogen atom of the group is substituted with an organic group.

The “organic group” is a group containing a carbon atom, and the organic group in the acrylate ester is not particularly limited. For example, in the structural units (a0), (a ′ l) to (a ′ 4) described later, etc. In the constituent units listed, groups bonded to the ester side chain of the acrylate ester (groups having a fluorinated hydroxyalkyl group, acid dissociable, dissolution inhibiting groups, ratatone-containing cyclic groups, polar groups) Aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group and the like.

In the acrylic acid, the α-position (the carbon atom at the α-position) is a carbon atom to which a carbonyl group is bonded, unless otherwise specified.

Examples of the substituent of α-substituted acrylic acid include a halogen atom, a lower alkyl group, a halogenated lower alkyl group and the like. Examples of the halogen atom as the substituent at the α-position include a fluorine atom, a chlorine atom, a bromine atom, a silicon atom, etc., and a fluorine atom is particularly preferred.

Specific examples of the lower alkyl group as a substituent at the α-position include methyl, ethyl, propyl, isopropyl, η-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl. And a lower linear or branched alkyl group such as a group.

The halogenated lower alkyl group as a substituent at the a-position is a group in which at least one or all of the hydrogen atoms of the lower alkyl group have been substituted with the halogen atoms.

Bonded to the α-position of acrylic acid is preferably a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, preferably a hydrogen atom, a fluorine atom, a lower alkyl group or a fluorinated lower alkyl group. Most preferred is a hydrogen atom or a methyl group from the viewpoint of easy industrial availability.

“Acrylic acid-derived structural unit” means a structural unit formed by cleavage of an ethylenic double bond of acrylic acid.

“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.

Examples of the structural unit (a) include structural units represented by the following general formula (a).

[0023] [Chemical 2]

[Wherein is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and X is a hydrogen atom or a monovalent organic group]

[0024] The halogen atom, lower alkyl group or halogenated lower alkyl group of R ^{2G is} the halogen atom, lower alkyl group or halogenated lower alkyl as the substituent at the a position. The same thing as a group is mentioned.

Examples of the organic group for X include the same as the above-mentioned “organic group in acrylic ester”.

[0025]榭脂(A1) is a structural unit (a), against the total of all the structural units that constitute the榭脂(A1), 50 to: be contained in a proportion of LOO mol ^_0/0 preferred instrument 70 to: LOO mol ^_0/0 it forces more preferable containing. In particular, since the effect of the present invention is particularly excellent, it is preferable that the rosin (A1) is a component that only has a structural unit (a) derived from acrylic acid.

Here, “only the structural unit (a) is covered” means that the main chain of the resin (A1) is composed only of the structural unit (a) and does not include other structural units. To do.

In the present invention, the resin (A1) preferably has a structural unit (aO) derived from an acrylate ester having a fluorinated hydroxyalkyl group in the side chain portion. .

Here, in the present specification and claims, the “side chain portion” means a portion not constituting the main chain.

Examples of the structural unit (aO) include structural units in which X in the general formula (a) is a group having a fluorinated hydroxyalkyl group.

In the present invention, it is particularly preferable that the structural unit (aO) force includes at least one structural unit represented by the following general formula (aO-1) or (aO-2).

[0027] [Chemical 3]

2c + 1

(a 0-1} (a 0-2)

Wherein, R ² is a hydrogen atom, an alkyl group, a halogen atom, a Harogeni spoon alkyl group; R ²¹ is an (e + 1) -valent aliphatic cyclic group or an (e + 1) -valent chain saturated aliphatic hydrocarbon group; R ²² and R ²³ are each independently a hydrogen atom or a monovalent aliphatic ring Wherein at least one of R ²² and R ²³ is an aliphatic cyclic group; d and f are each independently an integer of 0 to 5; b and c are each independently 1 to 5 E is an integer of 1 to 3. ]

[0028] Examples of R ^2G in the general formula (aO-l) include those similar to R ^2G in the above-described formula (a). R ² in the general formula (aO-l) is preferably a hydrogen atom or an alkyl group, U,. Preferable to be particularly hydrogen atom or a methyl group

[0029] R ²¹ is an (e + 1) -valent aliphatic cyclic group or an (e + 1) -valent chain saturated aliphatic hydrocarbon group.

Here, in the present specification and claims, “aliphatic” is a relative concept with respect to aromaticity, and is defined to mean a group, compound, or the like that does not have aromaticity.

“(E + 1) -valent aliphatic cyclic group” means a group obtained by removing (e + 1) hydrogen atoms bonded to carbon atoms constituting the ring skeleton of the aliphatic cyclic group.

In addition, `` (e + l) -valent chain saturated aliphatic hydrocarbon group '' removes (e + 1) hydrogen atoms from a chain (straight chain or branched chain) saturated aliphatic hydrocarbon! Means a group.

[0030] The aliphatic cyclic group may be monocyclic or polycyclic. “Monocyclic aliphatic cyclic group” means a monocyclic group having no aromaticity, and “polycyclic aliphatic cyclic group” means a polycyclic group having no aromaticity. Means a cyclic group.

An aliphatic cyclic group is a hydrocarbon group consisting of carbon and hydrogen (alicyclic group), and at least one carbon atom constituting the ring of the alicyclic group is an oxygen atom, nitrogen atom, sulfur atom, etc. Heterocyclic groups substituted with a tera atom are included. As the aliphatic cyclic group, an alicyclic group is preferable.

The aliphatic cyclic group may be either saturated or unsaturated, but is preferably saturated because it is highly transparent to ArF excimer laser, etc., and has excellent resolution and depth of focus (DOF). .

The aliphatic cyclic group preferably has 3 to 20 carbon atoms, more preferably 4 to 15 carbon atoms, and even more preferably 5 to 15 carbon atoms. As a specific example of the aliphatic cyclic group, the monocyclic group includes a hydrogen atom substituted with a fluorinated hydroxyalkyl group from cycloalkane (hereinafter the same), and (e + 1) Examples include groups in which the above hydrogen atoms have been removed. More specifically, a group obtained by removing (e + 1) or more hydrogen atoms from cyclopentane or cyclohexane, and a group obtained by removing (e + 1) hydrogen atoms from cyclohexane. Favored ,.

Examples of the polycyclic group include groups in which at least (e + 1) or more hydrogen atoms are removed, such as bicycloalkane, tricycloalkane, and tetracycloalkane. More specifically, groups obtained by removing (e + 1) or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane can be used. Many such polycyclic groups have been proposed as constituents of acid dissociable, dissolution inhibiting groups in, for example, resin for positive photoresist compositions for ArF excimer laser processes! Force Can be selected as appropriate.

Due to industrial availability, monocyclic groups are preferably cyclopentane and cyclohexane with (e + 1) or more hydrogen atoms removed, especially (e + 1) from cyclohexane. A group in which the above hydrogen atom is removed is preferable. Further, as the polycyclic group, a group in which (e + 1) or more hydrogen atoms are removed from adamantane, norpolnan, or tetracyclododecane is preferable, and in particular, (e + 1) or more hydrogen atoms are removed from norbornane. !

As the aliphatic cyclic group for R ^21, a group in which (e + 1) hydrogen atoms are removed from cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like is preferable. In particular, a group obtained by removing (e + 1) hydrogen atoms from norbornane or a group obtained by removing (e + 1) hydrogen atoms from cyclohexane is preferred.

[0031] The (e + 1) -valent chain saturated aliphatic hydrocarbon group of R ²¹ may be linear or branched, and preferably has 1 to 10 carbon atoms. It is more preferable.

Specific examples include groups obtained by removing (e + 1) hydrogen atoms of saturated aliphatic hydrocarbon power such as methane, ethane, propane, butane, 2-methylpropane, and 2-methylbutane.

In the general formula (aO-1), b and c are each independently an integer of 1 to 5, preferably an integer of 1 to 3, and 1 is most preferable. d is an integer of 0 to 5, and an integer of 0 to 3 is preferable. 0 or 1 is particularly preferable.

e is an integer of 1 to 3, and is preferably 1 or 2.

[0033] As the structural unit represented by the general formula (aO-1) (hereinafter referred to as the structural unit (aO-1)), R ²¹ in the general formula (aO-1) is an aliphatic cyclic group. In particular, a constituent unit represented by the following general formula (aO—1-1) or (aO—1-2) is preferable.

[0034] [Chemical 4]

[Wherein R ^u , b and c are the same as above, and a and a ′ are each independently an integer of 0 to 5. [0035] The structural unit represented by the general formula (aO—1 1) is a fluorinated hydroxyalkyl group in which one of the hydrogen atoms of the norbornyl group is a specific fluorinated group [one (CH) — C (CF) ( CF) —

2 a b 2b + l c 2c + l

Is a structural unit containing a group substituted with OH].

R ² in formula (aO-1-1-1) is preferably a hydrogen atom or a lower alkyl group, particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

a is an integer of 0 to 5, preferably 0 to 3, and most preferably 1. In the general formula (aO— 1— 1), in particular, — (CH 2) — C (C F) (C F) —OH

2 a b 2b + l c 2c + l Bonding to the 5th or 6th position of the carbonyl group is preferred from the point of force effect and easy synthesis and high etching resistance.

The structural unit represented by the general formula (aO—12) contains a group in which two hydrogen atoms of the cyclohexyl group are substituted with one (CH 3) —C (CF 3) (CF 2) OH. Is a structural unit

2 a 'b 2b + l c 2c + l

The R ^2U in the formula (aO-1-2) is preferably a hydrogen atom or a lower alkyl group, particularly preferably a hydrogen atom or a methyl group, and most preferably a methyl group.

a ′ is an integer of 0 to 5, preferably an integer of 0 to 3, with 0 being most preferred. In the general formula (aO— 1— 2), in particular, — (CH 2) — C (C F) (C F) —OH

2 a 'b 2b + lc 2c + l is preferred from the viewpoint of force effect and easy etching and high etching resistance.ヽ.

[0037] In the structural unit represented by the general formula (aO-2) (hereinafter referred to as the structural unit (aO-2)), one hydrogen atom in the methyl group is one (CH) -C (CF). (CF) —OH and 1 or 2

2 f b 2b + l c 2c + l

A structural unit having a group substituted with an aliphatic cyclic group.

R ² in the general formula (aO-2) is preferably a hydrogen atom or a lower alkyl group, particularly preferably a hydrogen atom or a methyl group, and most preferably a methyl group.

b and c are the same as b and c in the above formula (aO-l).

f is preferably an integer of 1 to 5, more preferably an integer of 1 to 3, with 1 being most preferred.

[0038] R ²² and R ²³ are each independently a hydrogen atom or a monovalent aliphatic cyclic group, and at least one of R ²² and R ²³ is an aliphatic cyclic group.

In the present invention, it is particularly preferable that one of R ²² and R ²³ is a hydrogen atom and the other is an aliphatic cyclic group.

Examples of the aliphatic cyclic group for R ²² and R ²³ are the same as those described above for the “aliphatic cyclic group”, and may be monocyclic or polycyclic.

The aliphatic cyclic group for R ²² and R ²³ preferably has 6 to 12 carbon atoms, more preferably 5 to 15 carbon atoms. Among them, a group in which one or more hydrogen atoms are removed from cyclohexane, cyclopentane, norbornane, tricyclodecane, or tetracyclododecane is particularly preferable. A group in which one or more hydrogen atoms are removed from norbornane, or cyclohexane Remove one or more hydrogen atoms from xane!

[0039] In the present invention, as the structural unit (aO-2), in particular, the structural unit force effect represented by the following general formula (aO-2-1) or (aO-2-2), and It is preferred because it is easy to synthesize and has high etching resistance. [0040] [Chemical 5]

[Wherein, f, b and C are the same as above. ]

In the present invention, the structural unit (aO) is the structural unit in which R ²¹ in the general formula (aO-1) is an aliphatic cyclic group, the structural unit (aO-2), or the like. In addition, it is preferable that the side chain portion is a structural unit having a fluorinated hydroxyalkyl group and a monocyclic or polycyclic aliphatic cyclic group, in particular, the above general formula (aO-1) — The structural unit represented by 1), (aO-1-2), (aO—2-1) or (aO-2-2) is preferred.

[0042] As the structural unit (aO), one type may be used alone, or two or more types may be used in combination.

Resin (A1), the proportion of the structural unit (aO-), relative to the combined total of all the structural units that constitute the resin (A1), 30~: L 00 Monore ^_0/0 force S Preferably, 50 to: L00 Monore ⁰ / ₀ force S is more preferable, 70-: 100 mol% is more preferable, with L00 mol% being more preferable. When it is 30 mol% or more, the effect of containing the structural unit (aO) is high. For example, high immersion medium resistance can be obtained even if the proportion of the resin (A1) in the component (A) is small. As a result, the lithography properties are improved.

[0043] 'Other structural units

The resin (A1) may contain other structural units other than the structural unit (aO) as long as the effects of the present invention are not impaired.

Other structural units are not particularly limited as long as they are not classified into the above structural units (aO) and do not have an acid-dissociable group. For ArF excimer lasers, KrF excimer lasers ( Preferably used for resist resin such as ArF excimer laser) A large number of devices that have been known in the prior art can be used. Specific examples of such other structural units include structural units (a ′ 2) to ( _a ′ 4) listed in the below-described rosin (A2).

[0044] Resin (A1) is a radical polymerization of monomers derived from each structural unit, such as azobisisobutyl-tolyl (AIBN) or dimethyl-2,2, -azobis (2-methylpropionate). It can be obtained by polymerization by a known radical polymerization using an initiator.

[0045] The mass average molecular weight (Mw; mass average molecular weight in terms of polystyrene by gel permeation chromatography) of the rosin (A1) is not particularly limited, but is preferably 2000-30000 force S, more preferably from 2000 to 10,000 force Preferably, 3000-7000 power is even more preferred! By setting it within this range, a good dissolution rate in an alkali developer can be obtained, which is preferable from the viewpoint of high resolution. Within this range, the lower the molecular weight, the better characteristics tend to be obtained.

The dispersity (MwZMn) is about 1.0 to 5.0, preferably 1.0 to 3.0.

[0046] The content of the rosin (A1) in the component (A) is preferably 0.1% by mass or more, more preferably in the range of 0.1 to 50% by mass. 0.1 to 25% by mass is more preferable 0.1 to 20% by mass is particularly preferable 0.1 to: LO% by mass is most preferable. When the content of rosin (A1) is 0.1% by mass or more, resistance to the immersion medium is improved. On the other hand, if it is 50% by mass or less, the balance with the resin (A2) becomes good, and the lithography properties are improved.

[0047] [Reed (A2)]

The resin (A2) is not particularly limited as long as it has a structural unit (a ′) derived from acrylic acid and does not contain a fluorine atom. One or two or more types of alkali-soluble or alkaline-soluble resins, which have been proposed as base resins for use, can be used. The former is a so-called negative resist composition, and the latter is a so-called positive resist composition.

[0048] As the structural unit (a '), R ² in the general formula (a) is a hydrogen atom, a halogen atom other than a fluorine atom, a lower alkyl group, or a halogen atom other than a fluorine atom. Examples thereof include a structural unit in which a child is a substituted lower alkyl group (halogen-lower alkyl group) and X is a hydrogen atom or a monovalent organic group not containing a fluorine atom.

[0049]榭脂(A2) is a structural unit (a '), against the total of all the structural units that constitute the榭脂(A2), 50 to: be contained in a proportion of LOO mol ^_0/0 preferred instrument 70 to: LOO mol ^_0/0 and more preferably contains. In particular, since the effect of the present invention is particularly excellent, it is preferable that the coconut resin (A2) has only the structural unit (a ′) from which the allylic acid is also derived.

Here, “only the structural unit (a,) also has a force” means that the resin (A2) includes only the structural unit (a,) and does not include other structural units.

[0050] · Unit (a, l)

When the resist composition for immersion exposure of the present invention is a positive resist composition, the resin (A2) is derived from an acrylate ester having no fluorine atom and containing an acid dissociable, dissolution inhibiting group. It is preferable to have a structural unit (a'1).

The acid dissociable, dissolution inhibiting group in the structural unit (a '1) has an alkaline dissolution inhibiting property that makes the entire resin (A2) insoluble in alkali before dissociation, and the entire resin (A2) after dissociation. As long as it is changed to alkali-soluble, those proposed so far as the acid dissociable, dissolution inhibiting group of the base resin for chemically amplified resists can be used. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. ing. “(Meth) acrylic acid” means either one of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the a-position. The term “(meth) acrylic acid ester” means either one of an acrylic acid ester having a hydrogen atom bonded to the _α- position and a methacrylic acid ester having a methyl group bonded to the _α- position.

[0051] Here, "tertiary alkyl ester" is an ester formed by substitution with a hydrogen atom of a carboxy group, a chain or cyclic alkyl group, and the carboxy group ( A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of 1 C (O) —0—). In this tertiary alkyl ester, when an acid acts, the bond is broken between the oxygen atom and the tertiary carbon atom. The chain or cyclic alkyl group may have a substituent!

Hereinafter, a group that becomes acid dissociable by constituting a carboxy group and a tertiary alkyl ester will be referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience. Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include aliphatic branched acid dissociable, dissolution inhibiting groups, and acid dissociable, dissolution inhibiting groups containing aliphatic cyclic groups.

The “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The aliphatic branched acid dissociable, dissolution inhibiting group is a tertiary alkyl having 4 to 8 carbon atoms. Specific examples of preferred groups include a tert butyl group, a tert-amyl group, and a tert-heptyl group.

[0053] The "aliphatic cyclic group" in the "acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group" is the same as the aliphatic cyclic group listed in the structural unit (aO-Ι). (Excluding those containing fluorine atoms).

Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group, specifically, 2-methyl 2-adamantyl. Group, 2-ethyl-2-adamantyl group and the like. Or, in a structural unit represented by the following general formula (al "), an aliphatic cyclic group such as an adamantyl group such as a group bonded to an oxygen atom of a carbo-oxy group (-C (O)-0-) And a group having a group and a branched alkylene group having a tertiary carbon atom bonded thereto.

[0054] [Chemical 6]

[0055] In the formula, R is a hydrogen atom, a halogen atom other than a fluorine atom, a lower alkyl group, or a lower alkyl group in which a hydrogen atom is substituted with a halogen atom other than a fluorine atom (halogen lower alkyl group). , R ¹⁵ and R ¹⁶ represent an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms).

Examples of the halogen atom, lower alkyl group, and halogenated lower alkyl group for R are the same as those exemplified as the halogen atom, lower alkyl group, and halogenated lower alkyl group for R ² in the general formula (a). (Excluding fluorine atoms and fluorinated alkyl groups).

[0056] "Acetal-type acid dissociable, dissolution inhibiting group" is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal type acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal type acid dissociable, dissolution inhibiting group is bonded. . Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (pi).

[0057] [Chemical 7]

[Wherein R ¹ ′ and R ″ each independently represents a hydrogen atom or a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or an aliphatic cyclic group.] [0058] In the above formula, n is preferably an integer of 0 to 2, 0 or 1 is more preferable, and 0 is most preferable.

Examples of the lower alkyl group for R ¹ ′ and R include the same lower alkyl groups as those described above for R, and a methyl group that is preferably a methyl group or an ethyl group is most preferable.

In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable, dissolution inhibiting group (pi) is preferably a group represented by the following general formula (pi-1).

[0059] [Chemical 8]

[Wherein R n and Y are the same as above. ]

[0060] Examples of the lower alkyl group of Υ include those similar to the lower alkyl group of R above.

As the aliphatic cyclic group, a large number of conventionally proposed ArF resists and the like can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups. Examples thereof are the same as the “aliphatic cyclic group”.

[0061] Further, examples of the acetal type acid dissociable, dissolution inhibiting group include groups represented by the following general formula (p2).

[0062] [Chemical 9]

[Wherein R "and R ¹⁸ are each independently a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ is a linear, branched or cyclic alkyl group, or R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. [0063] In R ^17, R ^18, the carbon number of the alkyl group is preferably 1 to 15, linear, branched either Yogu Echiru group, and most preferably preferred instrument methyl group is a methyl group . In particular, one of R ¹⁷ and R ¹⁸ is preferably a hydrogen atom and the other is a katyl group.

R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be linear, branched or cyclic.

When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.

When R ¹⁹ is cyclic, it is preferably 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and further preferably 5 to carbon atoms: LO is most preferable. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. And the like, in which a hydrogen atom is removed. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. It is done. Among them, a group in which one or more hydrogen atoms are removed from adamantane is preferable.

In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ^{19 and} the end of R ¹⁷ The end may be bonded. In this case, a cyclic group is formed by R ¹⁷ and R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydrovinyl group and a tetrahydrofuranyl group.

[0064] As the structural unit (al), a structural unit represented by the following general formula (al-0-1) and a structural unit force represented by the following general formula (al-0-2) are selected. It is preferable to use one or more.

[0065] [Chemical 10]

[Wherein, R is as defined above; X ¹ represents an acid dissociable, dissolution inhibiting group. ]

[Chemical 11]

■ (a 1-0-0-2)

[Wherein, R is as defined above; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents an alkylene group or an aliphatic cyclic group. ]

In the general formula (al-0-1), R is the same as described above.

X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. Tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred.

In the general formula (al-0-2), R is the same as described above.

X ² is the same as X ¹ in the formula (al-0-1).

Y ² is preferably an alkylene group having 1 to 4 carbon atoms or a divalent aliphatic cyclic group, except that a group in which two or more hydrogen atoms are removed is used as the aliphatic cyclic group. The same as the explanation of the “aliphatic cyclic group” can be used.

[0069] More specifically, the structural unit (al) includes structural units represented by the following general formulas (al-1) to (al-4).

[0070] [Chemical 12]

{a

[In the above formula, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group; Y represents a lower alkyl group having 1 to 5 carbon atoms or an aliphatic cyclic group; n represents 0 to 3 M represents 0 or 1; R is as defined above; R ¹ ′ and R ² ′ each independently represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. ]

[0071] At least one of the R ¹ 'and R ² ' is preferably a hydrogen atom, more preferably a hydrogen atom. n is preferably 0 or 1.

X ′ is the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group exemplified for X ¹ above.

Examples of the aliphatic cyclic group for Y include the same groups as those exemplified above in the explanation of the “aliphatic cyclic group”.

Specific examples of the structural units represented by the general formulas (al-1) to (al-4) are shown below.

[0072] [Chemical 13] ccl

(a1— 1-12) (a1— 1— 13)

14]

(a1-1-17) (a1-1-18)

15]

[0075] [Chemical 16]

[0076] [Chemical 17]

[OZ ^ [6 00]

Sl76lS0 / .00Zdf / X3d 63 60 / 00Z OAV

(a1-3-13) (a1- 3-14) <a1-3-15) (a 卜 3-16)

(a 1-3-21) (al— 3-22) (a1-3-23) (a1-3-24)

[ZZ ^ [2800]

60 / 00Z OAV

(a1 -4-30)

Among these, specifically, the structural unit represented by the general formula (al-1) is preferred (al 1 1) to (al-1 1-6) or (al-1 35) to (al-1 It is more preferable to use at least one selected from the structural units represented by —41).

Furthermore, as the structural unit (a ′ 1), in particular, those represented by the following general formula (al—011) including the structural units of the formulas (al 1-1) to (al 1-4): In addition, the following general formula (al—102) that includes the structural units of the formulas (al—35) to (al—1—41) is also preferable. [0084] [Chemical 24]

(Wherein R is as defined above, and R ¹¹ represents a lower alkyl group.)

[Chemical 25]

(Wherein R is the same as above, R ¹ represents a lower alkyl group, h represents an integer of 1 to 3)

[0086] In the general formula (al-1-01), R is the same as described above. The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group! /. In the general formula (al-1-02), R is the same as described above. Lower alkyl group of R ¹² is the same as the lower alkyl group for R, and most preferably preferred instrument Echiru group is a methyl group or Echiru group. h is preferably 1 or 2, and most preferably 2.

In rosin (A2), as the structural unit (a ′ 1), one type may be used alone, or two or more types may be used in combination.

During榭脂(A2), the proportion of the structural unit (a '1), the total of all structural units constituting the榭脂(A2), 10 to 80 Monore ^_0/0 force S Preferably, 20-70 Monore ^_0/0 more preferably the force S, 30 to 60 Monore ^_0/0 force S more preferred. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is obtained, and by setting the upper limit value or less, it is possible to balance with other structural units. it can.

[0088] · Structural unit (a, 2)

In addition to the structural unit (a ′ 1), rosin (A2) has a structural unit (a ′ 2) derived from an acrylate ester that does not have a fluorine atom and contains a latatotone-containing cyclic group. Is preferred.

Here, the ratatone-containing cyclic group refers to a cyclic group containing one ring (lataton ring) containing a -o-c (o) structure. The rataton ring is counted as the first ring, and if it is only a rataton ring, it is called a monocyclic group, and if it has another ring structure, it is called a polycyclic group regardless of the structure.

The lathetone-containing cyclic group of the structural unit (a '2) can be used to increase the adhesion of the resist film to the substrate or to a developer containing water when the resin (A2) is used for forming a resist film. It is effective in increasing the affinity of.

As the structural unit (a ′ 2), any unit can be used without any particular limitation.

Specifically, examples of the latatatone-containing monocyclic group include groups in which one or more hydrogen atoms have been removed from γ-petit-latatotone. In addition, examples of the radon-containing polycyclic group include groups obtained by removing one or more hydrogen atoms from a bicycloalkane, tricycloalkane, or tetracycloalkane having an radon ring.

[0090] More specifically, examples of the structural unit (a'2) include structural units represented by the following general formulas (a2-1) to (a2-5).

[0091] [Chemical 26]

[Wherein, R is the same as above, R ′ is a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and m is an integer of 0 or 1.] ] R in the general formulas (a2—l) to (a2-5) is the same as R in the structural unit (a ′ 1).

The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (a ′ 1).

In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.

Specific examples of the structural units of the general formulas (a2-1) to (a2-5) are shown below.

[0093] [Chemical 27]

[0094] [Chemical 28]

[¾009

o 1c-12c ] 06009

OAV

[]

§0

Among these, it is preferable to use at least one selected from the general formulas (& 2-1) to (& 2-5) V, and the general formulas (a2-1) to (a2— It is preferable to use at least one selected from 3). Specifically, the chemical formulas (a2— 1 1), (a2—l— 2), (a2— 2— 1), (a2— 2— 2), (a2— 3— l), (a2— 3— It is preferable to use at least one selected from 2), (a2-3-9) and (a2-3-10) forces.

In the resin (A2), as the structural unit (a ′ 2), one type may be used alone, or two or more types may be used in combination.

Ratio of榭脂(A2) structural unit in (a '2), relative to the total of all the structural units that constitute the榭脂(A2), 5 to 70 Monore ^_0/0 force S Preferably, 10 to 60 more preferably Monore ^_0/0 power S, more preferably 20 to 50 Monore%. By making it the lower limit value or more, the effect of containing the structural unit (a ′ 2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.

[0100] · Structural unit (a, 3)

In addition to the structural unit (a ′ 1) or in addition to the structural units (a ′ 1) and (a ′ 2), rosin (A2) has no fluorine atom and has a polar group-containing aliphatic carbonization. Acrylic acid containing hydrogen groups It is preferable to have a structural unit (a ′ 3) derived from Steruka. By having the structural unit (a'3), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contribute

Examples of the polar group include a hydroxyl group, a cyano group, and a carboxy group, and a hydroxyl group is particularly preferable.

Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). . As the polycyclic group, for example, a resin selected from a large number of proposed resins for ArF excimer laser resist compositions can be used. The polycyclic group preferably has 7 to 30 carbon atoms.

Among them, a structural unit derived from an acrylate ester group containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group or a carboxy group is more preferred. Examples of the polycyclic group include groups in which one or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane or the like. Specific examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Among these polycyclic groups, two or more hydrogen atoms are removed from adamantane, two or more hydrogen atoms are removed from norbornane, and two or more hydrogen atoms are removed from tetracyclododecane. The industrial group is preferred.

[0101] As the structural unit (a'3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to: LO, A structural unit derived from a hydroxyethyl ester is preferred. When the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1) and a structure represented by (a3-2) Units are preferred.

[0102] [Chemical 32]

(In the formula, R is the same as described above, j is an integer of 1 to 3, and k is an integer of 1 to 3.) [0103] In the formula (a3-l), j is 1 or 2 1 is more preferred. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group. j is preferably 1, and in particular, a hydroxyl group bonded to the 3-position of the adamantyl group is preferred.

In formula (a3-2), k is preferably 1. The cyan group is preferably bonded to the 5th or 6th position of the norbornyl group.

[0104] As the structural unit (a'3), one type may be used alone, or two or more types may be used in combination.

During榭脂(A2), the proportion of the structural unit (a '3) is the total of all structural units constituting the榭脂(A2), 5 to 50 mole ^_0/0 preferably fixture 5-40 it is more preferably mole ^_0/0 force S, and still more preferably 5 to 25 mol%.

[0105] · Structural unit (a, 4)

The resin (A2) may contain other structural units (a, 4) other than the structural units (a ′ l) to (a ′ 3) as long as the effects of the present invention are not impaired. .

The structural unit (a ′ 4) is not particularly limited as long as it is another structural unit that does not contain a fluorine atom and is not classified into the above structural units (a ′ l) to (a ′ 3). ArF A number of hitherto known materials can be used for resists such as excimer lasers and KrF excimer lasers (preferably for ArF excimer lasers). is there.

As the structural unit (a ′ 4), for example, a structural unit that also induces an acrylate force including a non-acid-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (al), for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser). A large number of conventionally known strengths can be used as the oil component of the resist composition.

In particular, at least one selected from a tricyclodecanyl group, a damantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. The hydrogen of these polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

Specific examples of the structural unit (a ′ 4) include those represented by the following general formulas (a4-l) to (a4-5).

[0106] [Chemical 33]

(Wherein R is the same as defined above.)

[0107] As the structural unit (a'4), one type may be used alone, or two or more types may be used in combination.

When the structural unit (a ′ 4) is contained in the resin (A2), the structural unit (a ′ 4) is added in an amount of 1 to 30 mol with respect to the total of all the structural units constituting the resin (A2). %, Preferably 10 to 20 mol%.

[0108] In the present invention, it is preferable that the resin (A2) is a copolymer having at least the structural units (a'1), (a'2) and (a'3). For example, the above configuration unit A copolymer comprising the positions (a, l), (a '2) and (a' 3), the structural units (a 'l), (a' 2), (a '

Examples thereof include a copolymer comprising 3) and (a ′ 4).

[0109] In the present invention, as the resin (A2), those containing three structural units represented by the following general formula (A2-11), (A2-12) or (A2-13) are particularly preferable. .

[0110] [Chemical 34]

^{^{Wherein, R 41, R 4d, R}} 44 each independently represent a hydrogen atom, a halogen atom other than a fluorine atom, a lower alkyl group or a hydrogen atom with a halogen atom other than fluorine atom substituted lower alkyl group (Harogeni spoon, R ⁴² is a lower alkyl group, R ⁴⁵ is a lower alkyl group, and R ⁴⁶ is a lower alkyl group. ] In formula (A2-11), the lower alkyl group for R ⁴¹ , R ⁴³ and R ^{44 is} the same as the lower alkyl group for R above. R ⁴¹ , R ⁴³ and R ⁴⁴ are preferably a hydrogen atom or a methyl group, preferably a hydrogen atom or a lower alkyl group. The lower alkyl group for R ^{42 is the same as} the lower alkyl group for R described above, and is most preferably a methyl group, preferably a methyl group or an ethyl group. In formula (A2-12), the lower alkyl groups for R ⁴¹ , R ⁴³ , and R ⁴⁴ are the same as described above. The lower alkyl group for R ^{45 is the same as} the lower alkyl group for R described above, and a methyl group is more preferable, and a methyl group is most preferable.

In formula (A2-13), the lower alkyl groups for R ⁴¹ , R ⁴³ and R ⁴⁴ are the same as described above. The lower alkyl group for R ^{46 is the same as} the lower alkyl group for R described above, and a methyl group or an ethyl group is preferred, and an ethyl group is most preferred.

[0112] The resin (A2) is obtained by polymerizing monomers for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyl-tolyl (AIBN). Therefore, it can be obtained.

[0113] Mass average molecular weight (Mw) of polystyrene (A2) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but preferably 2000 to 50000, more preferably 3000 to 30000 force. <, 5000-20000 power is the most preferred! If it is smaller than the upper limit of this range, it is sufficiently soluble in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.

Further, the degree of dispersion (Mw / Mn) i is preferably 1.0 to 5.0 force S, more preferably 1.0 to 3.0 force S, and most preferably 1.2 to 2.5.

[0114] Among the components (A), rosin (A2) may be used alone or in combination of two or more.

It is preferable that the content of sesame resin (A2) in component (A) is in the range of 50 to 99.9% by mass. 80 to 99.9% by mass is more preferable. 90 to 99.9% by mass % Is more preferable. Lithium (A 2) content power of 50% by mass or more improves lithography characteristics, and 99.9% by mass or less improves the balance with rosin (A1). Improves immersion medium resistance.

[0115] <(B) component> The component (B) is not particularly limited, and those that have been proposed as acid generators for chemical amplification resists can be used. Examples of such acid generators include onium salt-based acid generators such as ododonium salts and sulfo-um salts, oxime sulfonate-based acid generators, bisalkyl or bisarylsulfonyldiazomethanes. Various kinds of acid generators such as diazomethane acid generators such as poly (bissulfol) diazomethane, nitrobenzilsulfonate acid generators, iminosulfonate acid generators, and disulfone acid generators are known.

[0116] Examples of the acid salt-based acid generator include an acid generator represented by the following general formula (b-O).

[0117] [Chemical 35]

[Wherein, ¹ represents a linear, branched, or cyclic alkyl group, or a linear, branched, or cyclic fluorinated alkyl group; R ⁵² represents a hydrogen atom, a hydroxyl group, a halogen atom, or a linear chain. Or a branched alkyl group, a linear or branched halogenated alkyl group, or a linear or branched alkoxy group; R ⁵³ is an aryl group that may have a substituent. ; U, and are integers 1 to 3; ]

In the general formula (b-0), R ⁵¹ represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic fluorinated alkyl group.

The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. The cyclic alkyl group preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and still more preferably 6 to C: L0.

The linear, branched or cyclic fluorinated alkyl group preferably has the same carbon number as the linear, branched or cyclic alkyl group. The fluorination rate of the fluorinated alkyl group (ratio of the number of substituted fluorine atoms to the total number of hydrogen atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%, Particularly, all hydrogen atoms are substituted with fluorine atoms. This is preferable because the strength of the acid increases.

R ⁵¹ is most preferably a linear alkyl group or a fluorinated alkyl group.

[0119] R ⁵² is a hydrogen atom, a hydroxyl group, a halogen atom, a linear or branched alkyl group, a linear or branched halogen alkyl group, or a linear or branched alkoxy group. .

In R ⁵² , examples of the halogen atom include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom, and a fluorine atom is preferable.

In R ⁵² , the alkyl group is linear or branched, and the carbon number thereof is preferably 1 to 5, particularly 1 to 4, and more preferably 1 to 3.

In R ⁵² , the halogenated alkyl group is a group in which at least one or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms. Examples of the alkyl group here are the same as the “alkyl group” in R ⁵² . Examples of the halogen atom to be substituted are the same as those described above for the “halogen atom”. In the halogenated alkyl group, it is more preferable that 50 to 100% of the total number of hydrogen atoms are substituted with halogen atoms, which is all that is desirable.

In R ⁵² , the alkoxy group is linear or branched, and the carbon number thereof is preferably 1 to 5, particularly 1 to 4, and more preferably 1 to 3.

Among these, R ⁵² is preferably a hydrogen atom.

[0120] R ⁵³ is an aryl group which may have a substituent, and the structure of the basic ring (matrix ring) excluding the substituent includes a naphthyl group, a phenyl group, an anthracene group, and the like. In view of the effects of the present invention and the absorption of exposure light such as ArF excimer lasers, a phenol group is desirable.

Examples of the substituent include a hydroxyl group and a lower alkyl group (straight or branched chain, preferably having 1 to 5 carbon atoms, particularly preferably a methyl group).

As the aryl group for R ⁵³ , those having no substituent are more preferable.

u "is an integer from 1 to 3, 2 or 3 is preferred, especially 3 Yes.

[0121] Preferable examples of the acid generator represented by the general formula (b-0) include the following.

[0122] [Chemical 36]

[0123] Other acid salt generators of the acid generator represented by the general formula (b-0) include, for example, the following general formula (b-1) or (b-2). The compound which is made is mentioned.

[0124] [Chemical 37]

[Wherein, ,, to “, R ⁵ ” to R ⁶ ”each independently represents an aryl group or an alkyl group; R ⁴ ” represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group; Representation: At least one of,, ~ represents an aryl group, and at least one of R ⁵ "to R ⁶ " represents an aryl group.]

In formula (b-1), “to” each independently represents an aryl group or an alkyl group. At least one of R to “represents an aryl group. Of,, to“, two or more are preferably aryl groups. R ^{lw to} R ³ ”are all aryl groups. Most preferred

The aryl group of R ^{lw to} R ³ "is not particularly limited, for example, an aryl group having 6 to 20 carbon atoms. In the aryl group, at least one or all of the hydrogen atoms may or may not be substituted with an alkyl group, an alkoxy group, a halogen atom, or the like. As the aryl group, an aryl group with 6 to: LO is preferred because it can be synthesized at low cost. Specific examples include a phenyl group and a naphthyl group.

Among the alkyl groups that may be substituted on the hydrogen atom of the aryl group, a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are preferred, preferably an alkyl group having 1 to 5 carbon atoms. Like U ヽ.

As the alkoxy group that may be substituted with a hydrogen atom of the aryl group, a methoxy group and an ethoxy group are preferred, with an alkoxy group having 1 to 5 carbon atoms being preferred.

The halogen atom that may be substituted with the hydrogen atom of the aryl group is preferably a fluorine atom.

The “˜” alkyl group is not particularly limited, and examples thereof include a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. From the viewpoint of excellent resolution, the number of carbon atoms is preferably 1 to 5. Specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, A decanyl group and the like can be mentioned, and a methyl group can be mentioned as a preferable one because it is excellent in resolution and can be synthesized at low cost.

Among these, R ^{lw to} R ³ ″ are most preferably a phenyl group or a naphthyl group, respectively.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group. The linear or branched alkyl group preferably has 1 to 10 carbon atoms. Most preferably, it is 1 to 4 carbon atoms.

The cyclic alkyl group is a cyclic group as shown by the above R ¹ ″, preferably a carbon number of 4 to 15 carbon atoms, more preferably a carbon number of 4 to 10 carbon atoms. Most preferably, the number is from 6 to 10.

The fluorinated alkyl group is most preferably 1 to 4 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. In addition, the fluorination rate of the fluorine-containing alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to: LO 0%, more preferably 50 to 100%, and in particular, all hydrogen atoms substituted with fluorine atoms are preferred because the strength of the acid becomes strong.

R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. Of R 5, ˜˜R ⁶ , at least one represents an aryl group. All of R ⁵ ″ to R ⁶ , are preferably aryl groups.

Examples of the aryl group of R ⁵ "to R ⁶ " include the same as the aryl group of,, ~ "

Examples of the alkyl group for R ⁵ "to R ⁶ " include the same alkyl groups as for,, to ".

Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenol groups. Those similar to - "(1 b) R ⁴ in the formula is as" the like R ⁴ of formula (b-2) in.

[0128] Specific examples of the sodium salt acid generator represented by the formulas (b-1) and (b-2) include difluoro-rhodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, Bis (4-tert-butylphenol) trifluoromethane sulfonate or nonafluorobutane sulfonate, trifluoromethane sulfonate of trifluorosulfone, heptafluoropropane sulfonate or nonafluorolob Tansusulfonate, tri (4 methylphenol) sulfurium trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfotrifluoromethane Lomethanesulfonate, its heptafluoropropanesulfone Or its nonafluorobutane sulfonate, monophenyl dimethyl sulfone trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, diphenol mono methinoles noreform trif Norelomethane sulphonate, its heptafluoro sulphonate sulphonate or its nonafluorobutane sulphonate, (4-methylphenol) diphenyl sulphotrifluoromethane sulphonate, its heptafluoropropane sulphonate Or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenyl Trifonoleomethane sulphonate of snorephonum, its hepta-fluoro-propane sulphonate or its nonafluorobutane sulphonate, tri (4-tert-butyl) phenol sulphone Nepto, its heptafluoronorthopropane sulfonate or its nonafluorobutane sulphonate, diphenol (11- (4-methoxy) naphthyl) snorephonium trifanololemethane sulphonate, its heptafunole propane sulphonone Or its nonafluorobutane sulfonate, di (1 naphthyl) phenol sulfone trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate. In addition, ohmic salts in which the ionic part of these ohmic salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

[0129] In addition, in the general formula (b-1) or (b-2), the anion part is replaced with a caron part represented by the following general formula (b-3) or (b-4). A -um salt-based acid generator can also be used (the cation moiety is the same as (b-1) or (b-2)).

[0130] [Chemical 38]

, ^SQ 2 o ₂ s— Y "

, X "... (b-3) (.-. (B-4)

s ^o 2 ns—Z "

[Wherein X "represents a C 2-6 alkylene group in which at least one hydrogen atom is replaced by a fluorine atom; Υ", Ζ "each independently represents at least one hydrogen atom is fluorine. Represents an alkyl group having 1 to 10 carbon atoms substituted with an atom.

[0131] X "is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 3 carbon atoms. 5 and most preferably 3 carbon atoms.

Υ "and Ζ" are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably It is C1-C7, More preferably, it is C1-C3.

The carbon number of the alkylene group of X "or the carbon number of the alkyl group of Υ" and Ζ " Within this range, a smaller value is preferred for reasons such as good solubility in a resist solvent.

In addition, in the alkylene group of X "or the alkyl group of Υ" and Ζ ", the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the higher the energy of 200 nm or less. And U is preferred because of its improved transparency to electron beams, and the proportion of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to LOO%. Most preferably, it is a perfluoroalkylene group or a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

[0132] In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and generates an acid upon irradiation with radiation. It is what has. Such oxime sulfonate acid generators are widely used for chemically amplified resist compositions, and can be arbitrarily selected and used.

[0133] [Chemical 39]

—— C = N— O— S0 ₂ — R ³¹

R ³² '· · · CB-1)

(In the formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

[0134] The organic group of R ³¹ and R ^{32 is} a group containing a carbon atom, and an atom other than a carbon atom (for example, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom (a fluorine atom, a chlorine atom, etc. ) Etc.).

As the organic group for R ³¹ , a linear, branched or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. The substituent is not particularly limited, and examples thereof include a fluorine atom and a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms. Here, “having a substituent” means that at least one or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent. The alkyl group has 1 to 20 carbon atoms. Preferred carbon number 1-10 is more preferred carbon Numbers 1 to 8 are more preferable. Carbon numbers 1 to 6 are particularly preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which at least one hydrogen atom is substituted with a halogen atom, and the fully halogenated alkyl group means that all hydrogen atoms are halogen atoms. An alkyl group substituted with a child is meant. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.

The aryl group is preferably 4 to 20 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 6 to 10 carbon atoms, more preferably LO. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. A partially halogenated aryl group means an aryl group in which at least one hydrogen atom is replaced with a halogen atom, and a fully halogenated aryl group means that all hydrogen atoms are halogen atoms. This means an aryl group substituted with.

As R ³¹ , in particular, an alkyl group having 1 to 4 carbon atoms having no substituent, or 1 carbon atom

~ 4 fluorinated alkyl groups are preferred.

[0135] The organic group for R ³² is preferably a linear, branched or cyclic alkyl group, aryl group or cyan group. Examples of the alkyl group and aryl group for R ³² include the same alkyl groups and aryl groups as those described above for R ³¹ .

R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

[0136] As the oxime sulfonate-based acid generator, more preferred are those represented by the following general formula (

Examples thereof include compounds represented by B-2) or (B-3).

[0137] [Chemical 40]

R ³ — C = —— 0—— SO, — R ³⁵

I

3 °… (B-2)

[In the formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogen group. It is an alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

[0138] [Chemical 41]

[In the formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenalkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. R ³⁸ is an alkyl group having no substituent or a halogenated alkyl group. p "is 2 or 3.]

[0139] Te you, the general formula (B- 2), Do no substituent of R ^33, an alkyl group or a halogenated alkyl group, 1 to carbon atoms: preferably be a L0 device carbon Numbers 1-8 are more preferred Carbon numbers 1-6 are most preferred.

R ³³ is more preferably a fluorinated alkyl group, preferably a halogenated alkyl group.

The fluorinated alkyl group in R ³³ is preferably fluorinated with 50% or more of the hydrogen atom of the alkyl group, more preferably 70% or more, and even more preferably 90% or more. I like it! /

[0140] The aryl group of R ³⁴ includes an aromatic hydrocarbon such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthracyl group, and a phenanthryl group. Ring force A group in which one hydrogen atom is removed, and a heteroaryl group in which at least one carbon atom constituting the ring of these groups is substituted with a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Can be mentioned. Of these, a fluorenyl group is preferred.

The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 4 carbon atoms, more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

[0141] The alkyl group having no substituent of R ³⁵ or the halogenated alkyl group has 1 to A carbon number of 1 to 6 which is preferably 10 is most preferable, and a carbon number of 1 to 6 is more preferable. R ³⁵ is more preferably a fluorinated alkyl group, preferably a halogenated alkyl group.

The fluorinated alkyl group in R ³⁵ preferably has 50% or more of the hydrogen atoms of the alkyl group fluorinated, more preferably 70% or more, and even more preferably 90% or more. This is preferable because the strength of the acid is increased. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

[0142] In the general formula (B-3), the alkyl group or the halogenated alkyl group having no substituent of R ³⁶ is an alkyl group or a group having no substituent of R ³³ described above. Examples thereof are the same as the halogenalkyl group.

Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups in which the aryl group strength of R ³⁴ is one or two hydrogen atoms removed.

Do no substituent of R ^38, the alkyl group or Harogeni spoon alkyl group, the same alkyl group or Harogeni spoon alkyl group containing no substituent group of the ⁵ like et be.

P "is preferably 2.

[0143] Specific examples of oxime sulfonate-based acid generators include α- (p-toluenesulfo-oxyximino) monobenzyl cyanide, α- (ρ chlorobenzene-sulfo-oxyoximino) -benzyl cyanide, α- ( 4-Nitrobenzenesulfo-luoxyimino) -benzyl cyanide, ichiichi (4-troo 2 trifluoromethylbenzenesulfo-ruximino) benzyl cyanide, α- (benzenesulfo-ruximino) —4-cyclopentyl cyanide-do , Α (Benzenesulfo-Luximinomino) — 2, 4 Dichlorobenzil cyanide, α — (Benzenesulfo-Luximinomino) — 2, 6 Dichlorobenzil cyanide, α (Benzenesulfo-Luximinomino) 4-methoxybenzyl cyanide , Α-(2-Clorobenzobenzo-Luximinomino) -4-methoxybenzyl cyanide, α-(Benzene Sulfone-ruximino) —Chen—2-ylacetonitrile, at- (4-dodecylbenzenesulfo-ruximino) —benzyl cyanide, α-[(ρ Toluenesulfo-roximino) -4-methoxyphenyl] acetonitrile, α [(Dodecylbenzenesulfo-Luximino ) —4-Methoxyphenyl] acetonitrile, α- (Tosyloximino) —4-Cerciadide, α (Methylsulfo-Luximinomino) — 1-Cyclopente-Lucetonitrile, α- (Methylsulfo-Luximinomino) — 1 —Cyclohexyl-acetonitrile, OC-(methylsulfo-ruximino) 1-cyclohepturacetonitrile, α (methylsulfo-ruximino) — 1-cyclootatulacetonitrile, at-(trifluoromethylsulfo- (Luoxyimino) — 1-cyclopente-acetonitrile, _α- (trifluoromethylsulfo-l-uoxyimino) -cyclohexylhexonitrile, α- (Ethylsulfo-Luoxyimino) -Ethylacetonitrile, OC- (Propylsulfo-Luoximino) - Puropirua Seto - Kishirusuru (to cyclo - _tolyl, α -Luoxyimino) -cyclopentylacetonitrile, a- (Cyclohexylsulfo-Luoxyimino) -Cyclohexylnitrile, a- (Cyclohexylsulfo-Luoxyimino)-1-Cyclopente-Luacetonitrile, a- (Ethylsulfo-Luoxyimino)- 1-Cyclopentylacetonitrile, α (Isopropylsulfo-ruximino) — 1-Cyclopenteru-nitronitrile, a-(η-Butylsulfonyloximino) 1-Cyclopentenylacetonitrile, α (Ethylsulfo-ruximino) — 1-cyclo Hexa-l-acetonitrile, α- (Isopropylsulfol-oxyximino) 1-cyclohex-l-acetonitrile, （( _η -butylsulfo-luoxyimino) 1-cyclohex-l-acetonitrile, α (methylsulfo-ruxoxy) Mino) -phenolacetonitrile, OC- (methylsulfo-hydroxyimino) -ρ-methoxyphenylacetonitrile, α- (trifluoromethylsulfo-hydroxyimino) -phenolaceto-tolyl, _α- (trifluoromethylsulfo- (Luoxyimino) -p-methoxyphenylacetonitrile, at- (Ethylsulfonyloxyximino) -p-methoxyphenylacetonitrile, α- (Propylsulfo-Luoxyimino) p-Methylphenylacetonitrile, α (Methylsulfo-Luoxyimino) ρ bromophenol -Luacetonitrile and the like.

Also disclosed in JP-A-9-208554 (paragraphs [0012] to [0014], [Chemical Formula 18] to [Chemical Formula 19]) !, Ruoxime sulfonate acid generator, WO2004Z074242A2 (65 to 85) The oxime sulfonate acid generators disclosed in Examples 1 to 40) on the page can also be suitably used. Moreover, the following can be illustrated as a suitable thing.

[0144] [Chemical 42]

[0145] [Chemical 43]

HjC One C = N One OSO _a —— (CH2) ₃ CH ₃

[0146] Among the above exemplified compounds, the following four compounds are preferred.

[0147] [Chemical 44]

CiH ₉ -0 ₂ S― O—— N = C ~ ~ C = N—— 0 one S0 ₂ one C ₄ H ₉

C! N L J C IN

H ₃ C—— C = M—— OS0 ₂ —— (CH ₂ ) ₃ CM ₃

H ₃ C— C = H—— OS0 ₂ —— (CH ₂ ) ₃ CHj

[0148] Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfol diazomethanes include bis (isopropylsulfol) diazomethane, bis (p toluenesulfol) diazomethane, bis (1 , 1-dimethylethylsulfol) diazomethane, bis (cyclohexylsulfol) diazomethane, bis (2,4 dimethylphenylsulfol) diazomethane, and the like.

Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552 and JP-A-11-035573 can also be suitably used. Examples of poly (bissulfol) diazomethanes include 1,3 bis (phenylsulfol diazomethylsulfol) pronone, 1, 4 disclosed in JP-A-11 322707. Bis (phenylsulfodiazomethylsulfol) butane, 1,6-bis (phenolsulfodiazomethylsulfol) hexane, 1,10-bis (phenolsulfoldiol) Zomethylsulfo) decane, 1,2-bis (cyclohexylsulfo-diazomethylsulfo) ethane, 1,3 bis (cyclohexylsulfo-diazomethylsulfo) propane, 1,6 bis (cyclohexylsulfo-) (Ludiamethylsulfol) hexane, 1,10-bis (cyclohexylsulfoldiazomethylsulfol) decane Can be mentioned.

[0149] As the component (B), one type of these acid generators may be used alone, or two or more types may be used in combination.

In the present invention, it is particularly preferable to use an onium salt having a fluorinated alkyl sulfonate ion as an ion as the component (B).

The content of the component (B) in the resist composition for immersion exposure of the present invention is 0.5 to 30 parts by mass, preferably 1 to: LO parts by mass with respect to 100 parts by mass of the component (A). By making it in the above range, pattern formation is sufficiently performed. In addition, a uniform solution can be obtained and storage stability is favorable, which is preferable.

[0150] <Optional component>

In the resist composition for immersion exposure according to the present invention, in order to improve the resist pattern shape, post exposure stability of the latent image formed oy the pattern-wise exposure of the resist layer, etc. Furthermore, a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) can be added as an optional component.

Since a wide variety of components (D) have already been proposed, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines, can be used arbitrarily from known ones. Is preferred. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have from 12 to 12 carbon atoms.

As an aliphatic amine, at least one hydrogen atom of ammonia NH has 1 or more carbon atoms.

Three

Examples include amines substituted with up to 12 alkyl groups or hydroxyalkyl groups (alkylamines or alkylalcoholamines) or cyclic amines.

Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-xylamine, n-ptylamine, n-octylamine, n-norlamin, n-decylamine; jetylamine, di-n-propylamine, di-n Dialkylamines such as ptyramine, di-n-octylamine, dicyclohexylamine; trimethylolamine, triethinoleamine, tri-n-propylamine, tri-n-butynoleamine, tri-n-xyllamin, tri-n-pentylamine, tri-n-ptyluamine, tri-n —Otatylamin, tri-n-noramine, tri-n-de-force, tri-n-dodecylamine And trialkylamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine and the like. . Among these, tri-n-pentylamine is most preferred, with trialkylamine having 5 to 10 carbon atoms being more preferred.

Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic ammine) or polycyclic (aliphatic polycyclic ammine).

Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. As aliphatic polycyclic amines, those having 6 to 10 carbon atoms are preferred.

—Diazabicyclo [4. 3. 0] — 5—Nonene, 1, 8—Diazabicyclo [5. 4. 0] — 7—Undecene, Hexamethylenetetramine, 1,4-Diazabicyclo [2. 2. 2] Octane Etc.

These can be used alone or in combination of two or more.

Component (D) is usually used in the range of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

The resist composition for immersion exposure of the present invention contains organic carboxylic acid and phosphorus as optional components for the purpose of preventing sensitivity deterioration and improving the resist pattern shape and stability with time. Oxanoic acid and its derivative power Group power At least one selected compound (E) (hereinafter referred to as component (E)) can be contained.

As the organic carboxylic acid, for example, acetic acid, malonic acid, citrate, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.

Examples of phosphorus oxoacids and derivatives thereof include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferred.

Examples of derivatives of phosphorus oxoacids include esters in which the hydrogen atom of the oxoacid is substituted with a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms and a carbon number of 6 ˜15 aryl groups and the like.

Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate. Examples of the phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid diol n-butenoresestenole, phenolinophosphonic acid, phosphonic acid diphenolinoestenole, and phosphonic acid dibenzyl ester.

Examples of phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.

As the component (E), one type may be used alone, or two or more types may be used in combination.

Component (E) is used in a proportion of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

[0152] The resist composition for immersion exposure according to the present invention further contains a miscible additive as desired, for example, an additional grease for improving the performance of the resist film, and a surface activity for improving the coating property. An agent, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

[0153] The resist composition for immersion exposure according to the present invention can be produced by dissolving a material in an organic solvent (hereinafter, also referred to as component (S)).

As the component (S), it is sufficient if each component to be used can be dissolved into a uniform solution. Any one of conventionally known solvents for chemically amplified resists can be used. Two or more kinds can be appropriately selected and used.

For example, latones such as γ-butyrolatatane; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-η-amyl ketone, methyl isoamyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, dipropylene Polyhydric alcohols such as glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, or the polyhydric alcohols or having the ester bond Monoalkyl ether of compound, monoalkyl ether such as monoethyl ether, monopropyl ether, monobutyl ether, etc. or ether such as monophenyl ether Derivatives of polyhydric alcohols such as compounds having a combination; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methoxy Esters such as methyl propionate and ethyl ethoxypropionate; Noleitenore, Cresinoremethinoleatenore, Diphenenoleatenore, Dibenzenoleatenore, Fenetonore, Butinolefenenoleatenore, Ethinorebenzene, Jetinorebenzene, Aminobenzene, Isopropylbenzene, Toluene, Xylene, Cymene And aromatic organic solvents such as mesitylene.

These organic solvents can be used alone or as a mixed solvent of two or more. Of these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.

A mixed solvent in which PGMEA and a polar solvent are mixed is preferable. The mixing ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, but is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Preferably within range! /.

More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. When PGM E is blended as a polar solvent, the mass ratio of PGMEA: PGME is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, more preferably 3: 7 to 7: Three.

In addition, as the component (S), a mixed solvent of at least one selected from among PGMEA and EL and γ-petit-mouth rataton is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70: 30-95: 5.

The amount of component (S) used is not particularly limited, but it is a concentration that can be applied to a substrate, etc., and can be appropriately set according to the coating film thickness. It is used so as to be in the range of 20% by mass, preferably 5 to 15% by mass.

[0154] The material can be dissolved in the component (S), for example, by simply mixing and stirring each of the above-mentioned components by a usual method. If necessary, a dissolver, a homogenizer, a three-roll mill, etc. You may disperse and mix using a disperser. Further, after mixing, the mixture may be filtered using a cocoon mesh or a membrane filter.

[0155] As described above, the resist composition for immersion exposure according to the present invention is suitable for an immersion medium such that the elution of a substance into the immersion solvent is suppressed. It has excellent resistance and also has good lithography characteristics, and when used as a resist in immersion exposure, a resist pattern can be formed without any practical problems. The reason why such a powerful effect can be obtained is not clear, but the resin (A1) contains a fluorine atom and has a structure having no acid-dissociable group, and the resin (A2) does not contain a fluorine atom. Therefore, when the resist film is formed using the resist composition for immersion exposure, the resin (A1) is distributed near the outer surface of the resist film, for example, the resin (A2) Compared to the case of using a single substance, the receding angle of the resulting resist film is increased, the falling angle is decreased to improve the resistance to the immersion medium, and the resin (A2) containing no fluorine atom is distributed inside. Thus, it is presumed that good lithography characteristics should be secured.

That is, the resist film formed using the resist composition for immersion exposure according to the present invention has a dynamic contact angle with respect to water (resist film) as compared with the case where only the resin (A2) is used as the component (A). The contact angle when the water droplet starts to fall when the waterfall is tilted: The contact angle (advance angle) at the front end point of the water drop direction and the contact angle (retreat angle) at the rear end point of the drop direction ), The fall angle (the tilt angle of the resist film when water drops fall when the resist film is tilted) changes. For example, the receding angle increases, while the falling angle decreases. In immersion exposure, as described above, the resist film comes into contact with an immersion solvent such as water during immersion exposure. Therefore, it is presumed that substance elution is affected by the characteristics of the resist film surface (for example, hydrophilicity or hydrophobicity). In the present invention, it is presumed that by using a specific component (A), these characteristics are changed, thereby causing substance elution.

[0156] Here, as shown in Fig. 1, when the receding angle is gradually tilted on the plane 2 on which the droplet 1 is placed, the droplet 1 moves on the plane 2 ( The top edge la of the droplet 1 when it begins to fall) is the angle 0 made by the plane 2 with respect to the plane 2, and the falling angle is the slope of the plane 2 when the droplet 1 begins to move (drop) on the plane 2 The angle is 0.

2

[0157] In this specification, the receding angle and the falling angle are measured as follows.

First, a resist composition solution was spin-coated on a 6-inch diameter silicon substrate.

The resist film is formed by heating for 90 seconds at a temperature of 90 ° C.

Next, the above resist film is measured using a commercially available measuring device such as AUTO SLIDING ANGLE: SA-30DM (manufactured by Kyowa Interface Science), AUTO DISPENSER: AD-31 (manufactured by Kyowa Interface Science). can do. [0158] In the resist composition for immersion exposure according to the present invention, the measured value of the receding angle in a resist film obtained using the resist composition is preferably 45 to 150 degrees. It is particularly preferred that the temperature is 55 to 130 degrees. 60 is preferred: The LOO degree is most preferred. When the receding angle is 45 degrees or more, the substance elution suppression effect during immersion exposure is improved. The reason is not clear, but one of the main factors can be related to the hydrophobicity of the resist film. In other words, because the immersion medium is water-based, such as water, it is highly hydrophobic, so that after immersion exposure is performed, the resist film surface force is rapidly removed when the immersion medium is removed. It is presumed that the media can be removed. When the receding angle is 150 degrees or less, the lithography characteristics and the like are good.

The resist composition for immersion exposure according to the present invention preferably has a measured value of the falling angle in a resist film obtained by using the resist composition of 36 ° or less and 10 to 36 °. Is more preferably 12-30 degrees, and most preferably 15-25 degrees. If the sliding angle is 36 degrees or less, the substance elution suppression effect during immersion exposure is improved. In addition, when the falling angle is 10 degrees or more, the lithography characteristics and the like are good.

[0159] The size of the receding angle and the falling angle depends on the composition of the resist composition for immersion exposure, for example, the mixing ratio of the resin (A1) and the resin (A2) in the component (A), the structural unit ( It can be adjusted by adjusting the ratio of a '3). For example, by setting the ratio of the resin (A1) in the component (A) to 1% by mass or more, the receding angle is greatly increased and the falling angle is smaller than when the resin (A2) is used alone. Become.

[0160] Furthermore, in the present invention, as described above, substance elution into the immersion solvent is suppressed, so that the resist film can be altered and the refractive index of the immersion solvent can be suppressed. Therefore, by suppressing changes in the refractive index of the immersion solvent, the undulation and LER of the formed resist pattern are reduced, and the lithography properties such as the shape are improved. Further, it is possible to reduce the contamination of the lens of the exposure apparatus, so that it is possible to contribute to the simplification of the exposure apparatus without having to take protective measures against these.

In addition, according to the resist composition for immersion exposure of the present invention, a resist pattern with high resolution can be formed, for example, a resist pattern having a dimension of 120 nm or less can be formed. In addition, the use of the resist composition for immersion exposure of the present invention suppresses the occurrence of diffeta and LER. Therefore, a resist pattern having a good shape can be formed.

In the resist composition for immersion exposure according to the present invention, since the resin (A1) used as the component (A) does not have an acid-dissociable group, for example, a positive type resin is generally used. Compared to rubbing resin (resin having acid dissociable, dissolution inhibiting group), it is used as a base resin for the dyst composition, and has advantages such as easy synthesis and availability at low cost.

[0161] <Resist pattern formation method>

Next, the resist pattern forming method of the present invention will be described.

The resist pattern forming method of the present invention includes a step of forming a resist film on a substrate using the resist composition for immersion exposure of the present invention, a step of immersing the resist film, and developing the resist film. Forming a resist pattern.

[0162] A preferred example of the method for forming a resist pattern of the present invention is shown below.

First, the resist composition for immersion exposure of the present invention is applied onto a substrate such as a silicon wafer with a spinner and the like, and then subjected to pre-beta (post-apply beta (PAB) treatment) to form a resist film. Form.

At this time, an organic or inorganic antireflection film may be provided between the substrate and the coating layer of the resist composition to form a two-layer laminate.

In addition, an organic antireflection film can be further provided on the resist film to form a two-layer laminate, and a three-layer laminate in which a lower antireflection film is further provided.

The antireflection film provided on the resist film is preferably soluble in an alkaline developer. The steps so far can be performed using a known method. The operating conditions and the like are preferably set as appropriate according to the composition and characteristics of the resist composition for immersion exposure to be used.

[0163] Next, immersion exposure (Liquid Immersion Lithography) is selectively performed on the resist film obtained above through a desired mask pattern. At this time, the space between the resist film and the lowermost lens of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in that state. .

The wavelength used for the exposure is not particularly limited, and can be performed using radiation such as an ArF excimer laser, a KrF excimer laser, or an F laser. Resist assembly that helps the present invention

2

The composition is useful for KrF or ArF excimer lasers, especially ArF excimer lasers. It is effective.

As described above, in the forming method of the present invention, during exposure, the immersion film is filled with the immersion medium between the resist film and the lowermost lens of the exposure apparatus, and exposure (immersion exposure) is performed in that state. At this time, the immersion medium is preferably a solvent having a refractive index that is larger than the refractive index of air and smaller than the refractive index of a resist film formed by using a resist composition for immersion exposure. The refractive index of the powerful solvent is not particularly limited as long as it is within the above range.

Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and the like.

[0165] Specific examples of the fluorinated inert liquid include C HC F, C F OCH, C F OC H, C

3 12 5 4 9 3 4 9 2 5

Examples include liquids mainly composed of fluorine-based compounds such as HF, and boiling point of 70 to 180 ° C.

5 3 7

The thing of 80-160 degreeC is more preferable. If the fluorinated inert liquid has a boiling point in the above range, it is preferable that the medium used for immersion can be removed by a simple method after the exposure is completed.

As the fluorinated inert liquid, a perfluorinated alkyl compound in which all the hydrogen atoms of the alkyl group are replaced with fluorine atoms is particularly preferred! /. Specific examples of the perfluorinated alkyl compound include perfluoroalkyl ether compounds and perfluoroalkylamine compounds.

More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl monotetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include: Perfluorotributylamine (boiling point 174 ° C.).

[0166] The resist composition for immersion exposure of the present invention is particularly sensitive to water and is excellent in sensitivity and resist pattern profile shape, so that water is used as a solvent having a refractive index larger than that of air. Preferably used. Water also likes cost, safety, environmental issues and versatility.

[0167] Next, after the immersion exposure step is completed, post-exposure heating (post exposure beta (P EB)) is performed, followed by development using an alkali developer composed of an alkaline aqueous solution. And preferably, water rinsing is performed using pure water. Water rinse, for example, turn the substrate While rolling, water is dropped or sprayed on the substrate surface to wash away the developer on the substrate and the resist composition for immersion exposure dissolved by the developer. Then, drying is performed to obtain a resist pattern in which the resist film (the coating film of the resist composition for immersion exposure) is patterned into a shape corresponding to the mask pattern. Example

[0168] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

The resin (A) -1 to (A) -4 used in the following Examples 1 to 11 and Comparative Examples 1 to 3 were prepared by using the following monomers (1) to (4). It is a homopolymer synthesized with reference to Japanese Patent Laid-Open No. 2005-232095 and Japanese Patent Laid-Open No. 2005-316352. The obtained resin was subjected to GPC measurement, and the mass average molecular weight (Mw) and dispersity (MwZMn) were determined. The results are also shown in Table 1.

For the resin (A) -5 to (A) -6 used in the following Examples 1 to 11 and Comparative Examples 1 to 3, the following monomers (5) to (8) were used for the known dropping polymerization method. Was used for copolymerization.

The obtained resin was subjected to GPC measurement, and the mass average molecular weight (Mw) and dispersity (MwZMn) were determined. The results are also shown in Table 1.

[0169] [Chemical 45]

[0171] [Table 1]

[0172] The structures of the resins (A) -1 to (A) -6 are shown below. In the formula, the number attached to the lower right of 0 indicates the ratio (mol%) of each structural unit.

[0173] [Chemical 47]

[0174] [Chemical 48]

[0175] Examples 1 to: LI, Comparative Examples 1 to 3

Each component shown in Tables 2-3 was mixed and dissolved to prepare a positive resist composition solution.

[0176] [Table 2]

[0177] [Table 3]

Each abbreviation in Tables 2-3 has the following meaning. The value in [] is the blending amount (part by mass).

(B) -1: 4-methylphenyldisulfolsulfonium nonafluoro-n-butanesulfonate.

(D) —1: Tri-n-pentylamine.

(S) — 1: Mixed solvent with PGMEA / PGME = 60/40 (mass ratio). The following evaluation was performed using the obtained positive resist composition solution.

The obtained positive resist composition solution was applied onto a silicon wafer having a diameter of 8 inches using a spinner, pre-betaed on a hot plate at 115 ° C for 60 seconds, and dried to obtain a resist having a thickness of 175 nm. A film was formed. After dropping one drop (50 1) of pure water onto the resist film, the receding angle and the falling angle were measured with the following apparatus and conditions (the receding angle and the falling angle before exposure).

AUTO SLIDING ANGLE: SA— 30DM (Kyowa Interface Science Co., Ltd.)

AUTO DISPENSER: AD—31 (manufactured by Kyowa Interface Science Co., Ltd.), <Analysis software (attached to the device): FAMAS>

[0180] In addition, a resist film is formed in the same manner as described above, and an open frame exposure (without using a mask) is performed with an ArF excimer laser (193 nm) using a simple exposure apparatus VUVES4500 (manufactured by RISOTEC Japan Co., Ltd.) The falling angle and the backward receding angle were measured in the same manner except that the exposure was performed (the receding angle and the falling angle after exposure).

[0181] Tables 4 to 5 show the measurement results of the receding angle and the falling angle of the resist film before and after exposure.

Further, among these results, from the results of Examples 1 to 3 and Comparative Example 1 and the results of Examples 6 to 11 and Comparative Examples 2 to 3, (A) -1 or ( A) —A graph was created with the ratio (mass%) of 4 on the horizontal axis and the receding angle and the falling angle (°) on the vertical axis. This graph is shown in Figs.

As shown in these results, Examples 1 to 1 in which (A) -1 to (A) -3 corresponding to rosin (A1) and (A) -5 corresponding to rosin (A2) were used in combination In comparison with Comparative Example 1 where (A) -5 was used alone, the tumbling angle was smaller both before and after exposure, and the receding angle was larger, and the difference in tumbling angle before and after exposure was different. The difference between the front and rear receding angles was getting smaller. In particular, when (A) -1 is used, even if the ratio of (A) -1 in component (A) is a very strong amount of 1% by mass, the tumbling angle and receding angle are large both before and after exposure. Changed.

Similarly, (A) -4 corresponding to rosin (A1) and (A) -6 corresponding to rosin (A2) are used in combination. Examples 6 to: In LI, compared to Comparative Example 2 in which (A) -6 alone was used, the falling angle was small both before and after exposure and the receding angle was large before and after exposure. The difference in the falling angle and the difference in the receding angle before and after the exposure were getting smaller. Further, (A) in component (A) - 4 fraction is 5 to 50 mass ^_0/0 in an exemplary. 8 to: L 1, compared with Comparative Example 3 that used alone (A) -4 In Example 8-10, the receding angle is large both before and after exposure, and the proportion of (A) -4 in the component (A) is 5 to 20% by mass. Compared with Comparative Example 3 using 4 alone, the sliding angle was smaller both before and after exposure!

[¾4]

Using the positive resist composition solutions of Example 1 and Comparative Example 1, a resist film was formed in the same manner as described above. Next, using a VRC310S (manufactured by S'S Co., Ltd.), a drop of pure water (50 μ 1) was moved at a constant linear velocity in a circle from the center of the wafer at room temperature. (The total contact area of the resist film in contact with the droplet was 221.56 cm ² ).

After that, the droplets are collected and analyzed using an analyzer, Agilent—HP 1100 LC—MSD (Agile Technologies), and the component (B) from the resist film before exposure is cut. The elution amount (molZcm ² ) of the on-part and the key-on part, and the elution amount (molZ cm ² ) of component (D) were measured, and their total amount (elution amount before exposure (molZcm ² )) was obtained. .

[0185] Further, a resist film is formed in the same manner as described above, and an open frame exposure (through a mask, using an ArF excimer laser (193 nm) using a simple exposure apparatus VUVES4500 (manufactured by RISOTEC Japan Co., Ltd.) Exposure).

Next, the exposed resist film was analyzed in the same manner as described above, and the elution amount (molZcm ² ) of the cation part and the anion part of the (B) component and the elution amount of the (D) component from the resist film after exposure. (molZcm ² ) was measured, and the total amount thereof (elution amount after exposure (molZcm ² )) was determined.

These results are shown in Table 6.

[0186] [Table 6]

[0187] As is clear from the above results, when the positive resist composition of Example 1 using (A) -1 and (A) -5 in combination was used, only (A) -5 was used. Compared with the positive resist composition of Comparative Example 1, the elution of the (B) component and the (D) component in the immersion medium (water) before and after the exposure processing is suppressed, and the components in the resist film are suppressed. The effect of suppressing elution was confirmed.

[0188] In the above evaluation, the amount of elution before exposure is for evaluating the amount of elution in the unexposed area when a resist pattern is formed by performing selective exposure, and the amount of elution after exposure is This is for evaluating the amount of elution in the exposed area. Therefore, since the substance elution into the immersion medium (water) has little power both before and after exposure, the resist composition forming method includes the step of immersion exposure of the resist composition for immersion exposure according to the present invention. It was confirmed that it can be suitably used for immersion exposure.

In addition, from the measurement results of the receding angle and the falling angle and the measuring result of the eluate, it is clear that there is a correlation between the increase of the receding angle and the decrease of the falling angle and the effect of suppressing substance elution. Talking. [0189] <Lithography properties>

An organic antireflection coating composition “ARC-29” (trade name, manufactured by Bruichi Science Co., Ltd.) was applied onto an 8-inch silicon wafer using a spinner, and 205 ° C, 60 ° C. on a hot plate. By baking for 2 seconds and drying, an organic antireflection film having a film thickness of 77 nm was formed. Then, the positive resist composition solutions of Examples 1 to 1 and Comparative Examples 1 and 2 obtained above were respectively applied onto the antireflection film using a spinner, and 115 ° on a hot plate. C. A pre-beta (PAB) treatment was performed under conditions for 60 seconds, followed by drying to form a resist film having a thickness of 175 ηm.

Next, ArF excimer laser (193 nm) was selectively irradiated through the mask pattern by ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2Z3 annular illumination). Then, PEB was processed at 115 ° C for 60 seconds, and further developed at 23 ° C with 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds, and then purified water was added for 30 seconds. The sample was rinsed with water and dried by shaking.

As a result, a line-and-space resist pattern (hereinafter referred to as an L / S pattern) having a line width of 12 Onm and a pitch of 240 nm could be formed in any of Examples 1 to 11 and Comparative Examples 1 and 2.

Further, when the LZS pattern thus obtained was observed with a scanning electron microscope (SEM), it was obtained using the positive resist compositions of Examples 1 to 11 and Comparative Examples 1 and 2. All of the LZS patterns had a good shape.

[0190] The resins (A) -7 to (A) -11 used in the following Examples 12 to 16 and Comparative Examples 4 to 6 are the monomers (5) to (8) and the monomers (9) to (9) Using (11) as a table, copolymerization was carried out using a known dropping polymerization method.

The obtained resin was subjected to GPC measurement, and the mass average molecular weight (Mw) and dispersity (MwZMn) were determined. The results are also shown in Table 7.

[0191] [Chemical 49]

[0192] [Table 7]

[0193] The structures of resins (A) -7 to (A) -11 are shown below.

In the formula, the number attached to the lower right of 0 indicates the ratio (mol%) of each structural unit, [0194] [Chemical 50]

[ΐ3 ^] [36 TO]

Sl76lS0 / .00Zdf / X3d 9Ζ 60 / 00Z OAV

(A)-1 1

[0196] Examples 12 to 16, Comparative Examples 4 to 6

Each component shown in Table ⁸ was mixed and dissolved to prepare a positive resist composition solution.

[0197] [Table 8]

[0198] Each abbreviation in Table 8 has the following meaning. The value in [] is the compounding amount (part by mass).

(A) -4, (B) -1, (D) -1, and (S) -1 are Examples 1 to 11 and Comparative Examples 1 to 3, respectively. This is the same as (A) -4, (B) -1, 1, (D) -1, and (S) -1.

(B) -2: Tefifer sulfone nonafluoro-n-butanesulfonate.

(D) -2: Triethanolamine.

(E) — 1: Salicylic acid.

(S) — 2: Mixed solvent with PGMEA / EL = 60/40 (mass ratio).

(S) — 3: Mixed solvent with PGMEA / EL = 80/20 (mass ratio).

[0199] Each of the obtained positive resist composition solutions was applied onto a silicon wafer having a diameter of 8 inches using a spinner, and pre-betaged for 60 seconds at a PAB temperature shown in Table 9 on a hot plate. The resist film with a film thickness of 175 nm was formed by drying.

With respect to the obtained resist film, the falling angle and the receding angle were measured and the substance elution was evaluated in the same manner as described above. The results are shown in Tables 9-10. For the substance elution evaluation, the elution amounts (mol / cm ² ) of the cation part (PAG +) and the pheon part (PAG-) of the component (B) and their totals are shown.

[0200] [Table 9]

[0201] [Table 10]

[02021 The results shown in Table 9 clearly show that the resin (A) -4 corresponding to the resin (A1) and the resin (A2) When using the positive resist compositions of Examples 12 to 16 in combination with the corresponding resin (A) -7 to (A) -11, Comparative Examples 4 to 6 using only resin (A2) In comparison, the receding angle of the resist film was large both before and after exposure, and the difference between the receding angle before exposure and the receding angle after exposure was strong.

Further, as is clear from the results in Table 10, when the positive resist compositions of Examples 12 to 16 were used, compared to Comparative Examples 4 to 6, they were immersed in the immersion medium (water) before and after the exposure treatment. The elution of component (B) was suppressed, and the elution suppression effect of the anion part (PAG-) was particularly strong. In addition, among the above Examples, Examples 13 to 15 containing 2 parts by mass of (A) -4 were particularly effective in suppressing elution with a small amount of elution.

[0203] Special Lithographic Properties>

An organic antireflection coating composition “ARC-29” (trade name, manufactured by Bruichi Science Co., Ltd.) was applied onto an 8-inch silicon wafer using a spinner, and 205 ° C, 60 ° C. on a hot plate. By baking for 2 seconds and drying, an organic antireflection film having a film thickness of 77 nm was formed. Then, the positive resist composition solutions of Examples 12 to 16 and Comparative Examples 4 to 6 obtained above were applied on the antireflection film using a spinner, respectively, and listed in Table 9 on a hot plate. A pre-beta (PAB) treatment was performed at PAB temperature for 60 seconds, followed by drying to form a resist film having a thickness of 175 nm.

Next, ArF excimer laser (193 nm) was selectively irradiated through the mask pattern by ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2Z3 annular illumination). Examples 12 to 13 were 110 ° C. for 60 seconds, Comparative Examples 4 and 14 were 100 ° C. for 60 seconds, Comparative Examples 5 and 15 were 90 ° C. for 60 seconds, Comparative Examples 6 and Example 1 6 was PEB-treated at 145 ° C for 60 seconds, then developed at 23 ° C with 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds, and then purified water was added for 30 seconds. The sample was rinsed with water and dried by shaking.

As a result, in any of Examples 12 to 16 and Comparative Examples 4 to 6, an LZS pattern having a line width of 120 nm and a pitch of 240 nm could be formed.

[0204] From the above results, the resist composition for immersion exposure according to the present invention using both the resin (A1) and the resin (A2) can be used for immersion exposure, such as suppression of substance elution during immersion exposure. Suitable as Obviously, the lithography properties are also good.

Industrial applicability

According to the present invention, a resist composition with reduced LWR and a method for forming a resist pattern can be provided, which is industrially useful.

Claims

The scope of the claims

[1] A resist composition for immersion exposure comprising a resin component (A) whose alkali solubility is changed by the action of an acid and an acid generator component (B) that generates an acid upon exposure,

The resin component (A) has a fluorine atom-containing resin (A1) having no acid-dissociable group, an acrylic acid power-derived structural unit (a ′), and a fluorine atom. A resist composition for immersion exposure comprising a resin (A2) that does not contain.

[2] The resist composition for immersion exposure according to [1], wherein the resin component (A) is a resin having an acid dissociable, dissolution inhibiting group and having increased alkali solubility by the action of an acid.

[3] The resist composition for immersion exposure according to [1], wherein the content of the resin (A1) in the resin component (A) is 0.1% by mass or more.

[4] The resist composition for immersion exposure according to [1], wherein the resin (A1) has a fluorinated hydroxyalkyl group.

5. The resist composition for immersion exposure according to claim 1, wherein the resin (A1) has a structural unit (a) derived from acrylic acid.

[6] The resist for immersion exposure according to claim 5, wherein the resin (A1) has a structural unit ( _& 0) derived from an acrylate ester having a fluorinated hydroxyalkyl group in a side chain portion. Composition.

[7] The resist composition for immersion exposure according to [6], wherein the structural unit (aO) contains at least one structural unit represented by the following general formula (aO-1) or (aO-2).

[Chemical 1]

[Wherein R is a hydrogen atom, an alkyl group, a halogen atom or a halogenated alkyl group; R 2 ¹ is an (e + 1) -valent aliphatic cyclic group or an (e + 1) -valent chain saturated aliphatic group R ²² and R ²³ are each independently a hydrogen atom or a monovalent aliphatic cyclic group, and at least one of R ²² and R ²³ is an aliphatic cyclic group; d, f is independently an integer from 0 to 5; b and c are each independently an integer from 1 to 5; e is an integer from 1 to 3. ]

[8] The liquid according to claim 1, wherein the resin (A2) has a structural unit (a′1) that has no fluorine atom and has an acid dissociable, dissolution-inhibiting group and is induced by allylic acid ester force. A resist composition for immersion exposure.

[9] the榭脂(A2) further does not have a fluorine atom, and Rataton content cyclic structural unit derived from § acrylic ester containing a group according to claim 8, further comprising a _(a '2) Resist composition for immersion exposure.

[10] The resin (A2) further has a structural unit (a′3) derived from an acrylate ester having no fluorine atom and containing a polar group-containing aliphatic hydrocarbon group. The resist composition for immersion exposure as described.

11. The resist composition for immersion exposure according to claim 1, comprising a nitrogen-containing organic compound (D).

[12] Claims 1 to: A step of forming a resist film on a substrate using the resist composition for immersion exposure according to any one of L 1, a step of immersion exposure of the resist film, the resist A resist pattern forming method including a step of developing a film to form a resist pattern.